Suspension system for surface effect ships



Oct. 12, 1965 s c. RETHQRST 3,211,247

SUSPENSION SYSTEM FOR SURFACE EFFECT SHIPS Filed March 25, 1963 4 Sheets-Sheet l INVENTOQ scorr c. lam/025T Oct. 12, 1965 c, RETHQRST 3,211,247

SUSPENSION SYSTEM FOR SURFACE EFFECT SHIPS Filed March 25, 1965 4 Sheets-Sheet 2 INVENTOR.

56077 6'. fiEfF/ORST Oct. 12, 1965 s. c. RETHORST SUSPENSION SYSTEM FOR SURFACE EFFECT SHIPS 4 Sheets-Sheet 3 Filed March 25, 1963 INVENTOQ SCOTT 6'. RETHORST Oct. 12, 1965 s. c. RETHORST 3,211,247

SUSPENSION SYSTEM FOR SURFACE EFFECT SHIPS Filed March 25, 1963 4 Sheets-Sheet 4 IN VENTOE SCOTT C. QETHUFST United States Patent 3,211,247 SUSPENSION SYRTEM FUR SURFACE EEEE CT SHIPS Scott C. Rethorst, 1661 Lombardy Road, Pasadena, (Ialif. Filed Mar. 25, 1963, Ser. No. 267,681 9 Claims. (Cl. I80--7) This invention relates to a suspension system for a surface effect ship (sometimes described as a ground effect machine and hereinafter referred to as a GEM). In particular, it relates to a means of maintaining air nozzles for the peripheral and compartmenting jets, and especially the side jets of a GEM, at a selected distance from the uneven surfaces of ground or water, thus minimizing the power required in the air emitted from such nozzles to form a pneumatic seal for the high pressure beneath a GEM.

Primary objects of the invention are: first, to seal from each other the areas different pressure above and below a GEM with a pneumatic seal extending longitudinally at the sides thereof; second, to minimize the power necessary to effectively maintain the pneumatic seal by assuring the close proximity of the jet nozzles to the surface being traversed; third, to provide a means of varying the length of the jet nozzles from the undersurface of a GEM so that the nozzles are equidistant from the surface being traversed, regardless of its contours; fourth, to control the up and down movement of the jet nozzles by using the reaction pressure between them and the surface as a signalling device which will call upon the GEMs air pressurization system to amplify the initial movement of the jet nozzles so that they are always equidistant from the surface, regardless of its contours; fifth, to supplement the reaction pressure with the energy of the jet air flow itself so that the movement of the jet nozzles does not require external power; sixth, to prevent the jet nozzles which emit the sealing air jet from dragging on the surface of the ground or water; seventh, to maintain an effectively channelled flow of air beneath a GEM deriving lift from its aerodynamic configuration and forward movement; eight, to divide the edge pneumatic seals longitudinally so that the resulting compartments of pressurized air beneath a GEM contribute to its roll stability; ninth, to control the angle of vanes within the jet nozzles so that by their forward or rearward deflection, braking or thrusting of the GEM is provided.

A further object of the invention is to extend the sealing effect of the hulls fitted longitudinally to they undersurface of a GEM, at the sides thereof, with elastic or telescopic appendages thereinafter referred to as linear tires) beneath them, each linear tire incorporating air ducts and jet nozzles to accomplish the primary objects.

With these and other objects in view, the invention comprises the novel organization of principles and the arrangement of parts hereinafter more particularly described and illustrated in the accompanying drawings. It is to be understood, however, that the aforementioned descriptions and drawings do not limit the scope of the invention from that expressed by the claims hereunto appended.

Of the accompanying drawings, forming part of this specification, in which like reference numerals designate like parts in the several views:

FIGURE 1 is a perspective view of a GEM fitted with side hulls beneath each of which a linear tire is appended.

FIGURE 2 is a side view of the GEM of FIGURE 1, showing the linear tire compressing and extending so that its lower edge conforms to the wave development of the surface the GEM is traversing.

3,211,247 Patented Oct. 12, 1965 FIGURE 3 is a cross-section view of the GEM illustrated in FIGURE 2, showing the linear tires in their normal or intermediate position.

FIGURE 4 is a mechanical analogy of the GEM and its suspension system shown in FIGURE 3.

FIGURE 5 is an enlarged view of the left hull of the GEM shown in FIGURE 3, with the linear tire appended thereto in its normal position.

FIGURE 6 is a view of the same GEM hull of FIG- URE 5, but showing the linear tire appended thereto in its fully compressed position.

FIGURE 7 is a view of the same GEM hull of FIG- URE 5, but showing the linear tire appended thereto in its fully extended position.

It is to be noted that FIGURES 6, 5, and 7, in this sequence, illustrate the complete range of movement of the linear tire from complete compression (FIGURE 6) through the normal position (FIGURE 5) to complete extension (FIGURE 7), adjusting to the wave development beneath it.

FIGURE 8 illustrates the several segments of the linear tire passing through a complete cycle of various stages of compression and extension as the GEM traverses an undulating surface.

FIGURE 9 is an enlarged View of the area of FIGURE 8 indicated, showing jet vanes, within the jet nozzles, deflected forward or rearward to give braking action or additional thrust to the GEM, or with differing deflection angles at either side of the GEM, providing control of yaw.

Referring now to the drawings in detail, and describing this invention as it is effected thereby, a GEM 20 as illustrated in FIGURE 1 is fitted with two catamarantype side hulls 21 and 22, below which are linear tires 23 and 24 respectively. The linear tire 24, on the left side of the GEM, is shown in FIGURE 2 conforming to the surface wave perturbations from the mean water level 25, by compressing to avoid contact with the wave crest 26 and extending to enter the wave trough 27.

The flexible sidewalls of the linear tires 23 and 24- extend downwards from their side hulls 21 and 22, as shown in the cross section view of FIGURE 3. The external jet nozzle 28s and the internal jet nozzle 281' of the left linear tire 24 direct pressurized air downwards and inwards from the venturi shaped ducts 302 and 301'. Jet nozzles 29c and 291' on the right linear tire 23 similarly direct pressurized air downwards and inwards from the ducts 31c and 311'.

The operation of the linear tires 23 and 24 of FIG- URE 3 provides uniform suspension for the GEM 20 at a constant height over an undulating surface analogous to a mechanical spring damping system as illustrated in FIGURE 4. The mass 32a, supported on the center spring 330 and damped by the device 34, is analogous to the GEM 20 of FIGURE 3, supported by the air cushion of base pressure p and damped by the leakage of air therefrom. The mass 32!), located on the left side of the analogy, connected to the mass 320 by the upper spring 331:! and damped by the upper device 3511, is analogous to the linear tire 24 on the left side of the GEM 20, supported by the air pressure in its venturis 349i, 343e, and its tube 38, and damped by the air flow therein. The support of this mass 32b on the lower spring 331', damped by the lower device 35!, is in turn analogous to the support of the linear tire 24 by the air cushion of pad pressure p thereunder, damped by the leakage of air therefrom.

The left linear tire 24 is shown in the normal or intermediate position by FIGURE 5. Ports 36 and 37 of the tube 33 are in line with the ports 3? and 40 of the linear tire 24, so that they admit into the tube 38 air of intermediate pressure p from the middle of the adjacent venturis 301' and Site.

The linear tire 24 is shown in the compressed position by FIGURE 6. Ports 41 and 42 of the tube 33 are in line with the ports 43 and 44 of the linear tire 24 so that they permit the low jet pressure p; at the narrow end of the venturis 301' and 39a to evacuate the tube 38. Stops 45 and 46 of the tube 38 act against stops 4'7 and 48 of the linear tire 24 to maintain the in-line positioning of ports 4-1 and 42 of the tube 38 with the ports 43 and 44 of the linear tire 24 and to effect the upward motion of the linear tire 24. Stops 49 and Stl of the linear tire 24- contact stops 59 and 60 of the hull 22 at the limit of upward movement of the linear tire 24. Stops 66 and 67 of the tube 38 contact stops 63 and 64 of the hull 22 at the limit of compression of the tube 38.

The linear tire 24 is shown in the extended position by FIGURE 7. Ports 51 and 52 of the tube 38 and ports 53 and 54 of the tire 24 are in line so that they admit into the tube 38 air of high stagnation pressure p from the wide end of the venturis 301' and 38a. Stops 55 and 56 of the tube 38 act against stops 57 and 58 of the linear tire 24 to maintain the in-line positioning of ports 51 and 52 of the tube 38 and ports 53 and 54 of the linear tire 24 and to effect the downward motion of the linear tire 24. Stops 61 and 62 of the linear tire 24 contact stops S9 and 6th of the hull 22 at the limit of downward movement of the linear tire 24. Stops 45 and 46 of the tube 38 contact stops 63 and 64 of the hull 22 at the limit of extension of the tube 38.

The linear tire 2dadjusting to the wave development beneath it is shown by the sequence of FIGURES 6, 5, and 7. The hull 22 remains at a constant height above the mean water level 25 (or above a completely smooth surface). A wave crest 26 causes an increase of pad pressure p and evacuation of the tube 38 by low jet pressure 17,-. A wave trough 27 causes a decrease of pad pressure p and inflation of the tube 38 by high stagnation pressure p Up and down movement of the linear tire 24 maintains the jet nozzles 281 and 28a a substantially constant distance from the undulating surface.

The tire 24 will normally remain in the intermediate position of FIGURE 5, and deviate therefrom only by the action of a rising or falling level of the water surface. Return of the tire to its intermediate position after the passage of a wave crest or trough may be assisted if desired by the action of suitable springs (not shown) or elasticity characteristics of the tire walls.

The left linear tire 24, whose action is identical to but independent of the right linear tire 23, is shown in the side view of FIGURE 8. The several segments of the tube 38 are shown at various stages of compression and extension as they react to wave crests 26 and wave troughs 27. Raising and lowering the walls of the linear tire 24 is effected by this motion of the segments of the tube 38.

An enlargement of the encircled area of FIGURE 8 is shown as FIGURE 9. Jet vanes 65 within the jet nozzles 28:: and 281' are capable of deflecting the air jet forward or rearward of the GEM 20 thus providing braking action or additional thrust.

Operation of this system may now be described in the following sequence for any transverse section of the tire. Over smooth surfaces the reaction pressure on the bottom of the tube (hereinafter referred to as the pad) is unchanging. The pad pressure p and the pressure admitted to the tube are balanced, retaining the elastic or telescopic walls of the linear tire in their neutral position, neither contracted nor extended.

In its passage over a rising wave, the pad experiences increased pad pressure p caused by the closer proximity of the water surface. The tube responds by moving upwards, thus closing the ports to the intermediate pressure p of the venturi and opening those adjacent to the jet nozzle with its lower pressure p,- at the venturis narrowest section. This initial movement of the tube may be regarded as a signal that is amplified by air pressures of the GEM primary air supply. The low pressure at the jet nozzles evacuates the tube, and permits the high 5 pad pressure to move the tube upwards. Through the action of the tube against stops, the walls of the adjacent linear tire are also raised.

When the wave crest falls away to the mean surface level, the pad pressure p is reduced, permitting the tube to extend and to open the ports of intermediate pressure p at the middle of the venturi. By the same motion of the tube the ports of low pressure adjacent to the jet nozzles are closed. Pressure within the tube is now increased and it extends again, acting on stops to lower the walls of the adjacent linear tire.

When the pad passes over a wave trough, the pressure p beneath it is further reduced and the tube extends once more. Ports of high stagnation pressure p at the widest end of the venturi are opened, and with the same motion the intermediate pressure ports are closed. The high pressure admitted to the tube causes its further downward movement. Action of the tube against stops of the adjacent linear tire results in the tire being lowered.

In returning to its mean level, the water surface increases the pad pressure, closing the high pressure ports and opening those of intermediate pressure. The pressure within the tube is thereby reduced and the resultant upward movement of the tube against stops of the linear tire causes the tire to be raised to the intermediate or new tral position.

The several segments of the tube act independently along its length so that one segment may be rising to accommodate a wave crest while another is falling to fill in a wave trough. In this manner the entire length of the tire may maintain a constant operational distance from the water surface.

Forward and aft deflection of the jet is accomplished by deflecting the jet vanes fore or aft. The resulting deflection of the air jets can be employed to assist the braking of the GEM or to supplement its thrust. Used independently at either side of the GEM, these variable deflection vanes can be employed to give a yawing moment to the GEM.

The varying pressures on the pad are a passive function of the GEMs motion over uneven surfaces. These pressures are employed as signal devices to move the tube up or down with respect to the tire, thus opening or closing the ports at appropriately high or low pressure regions of the venturi. The air pressure so admitted forces the tube against stops to cause a corresponding contraction or extension of the linear tire wall, maintaining its jet nozzles at the desired distance from the surface.

The use of two jet nozzles, separated by the width of the tube in the linear tire beneath each hull, provides four longitudinal pneumatic seals beneath the GEM. The resulting compartmenting of the pressurized air on which the GEM is supported gives the GEM stability in roll.

While one method of employing the invention has been herein described and illustrated, it is to be understood that the invention lends itself to numerous other embodiments without departing from its basic principles.

Having thus described my invention, what I claim as novel and desire to secure by Letters Patent of the United States is:

I. In a suspension system for GEMs, means defining a pressure chamber of variable volume and including a member disposed underneath said GEM, said member being capable of moving relative to said GEM towards and away therefrom thereby changing the volume of said chamber;

means including movable nozzle means for directing pressurized air from said GEM toward the surface underneath thereof and establishing a pressure cushion underneath said GEM and said member,

the position of said member at any instant being determined by the pressure balance between the pressure in said chamber and the pressure of said cushion underneath said member;

and means for coupling said member directly to said movable nozzle means so that said nozzle means follow the movement of said member to change the distance of said nozzle means from said GEM in response to variations of said pressure balance.

2. In a suspension system for GEMs, a stationary member;

a movable control member establishing with said stationary member a deflatable and inflatable chamber of variable volume;

variable pressure inlet means formed in said control member to selectively provide said chamber with diflerent pressures to vary the volume of said chamber;

nozzle means for establishing an air cushion underneath said GEM and said removable control member outside of said chamber;

and means for coupling said nozzle means directly to said movable control member during inflation and deflation of said chamber, to change the distance of said nozzle means from said GEM.

3. In a suspension system for GEMS, a nozzle movably disposed in said GEM for directing an air jet towards the ground at a variable distance from the bottom of said GEM;

a duct of decreasing cross section communicating with said nozzle, said duct being provided with a plurality of outlets disposed at points of different cross section of said duct;

a tube of variable volume including a movable member having apertures selectively communicating with said outlets for establishing different pressures in said tube as determined by the respective pressures at said points, whereby the volume of said tube changes in accordance with any changes in the pressure on said tube;

means, being exposed to the pressure underneath a portion of said GEM and being coupled to said member to be responsive to the pressure balance between the air pressure underneath said portion of said GEM and the pressure in said tube and moving said member in response to variations in pressure balance; and

means for coupling said member to said nozzle to cause said nozzle to follow the movement of said member as resulting from a change of said pressure balance.

4. In a suspension system for GEMs, means defining a pressure chamber, a first, movable member included in said means and being positioned for varying the volume of said chamber;

means for introducing relatively high pressurized air into said chamber upon adjustment of said first member in a first direction;

means for introducing relatively low pressurized air into said chamber upon adjustment of said first member in a second direction;

a second member responsive to the pressure underneath said GEM and being coupled to said first member to move said first member in response to any change in the pressure balance of the pressure underneath said GEM adjacent said second member and the pressure in said chamber;

a movable nozzle directing pressured air underneath said GEM;

and means coupling said nozzle to said first member to follow movements of said first member in said first and second directions.

5. In a suspension system for GEMs, means defining a deflatable pressure chamber, the degree of expansion of said chamber being determined by the pressure balance between the pressure underneath said GEM and the pressure in said chamber;

duct means terminating in a nozzle for directing an air jet stream underneath said GEM said duct means 5 having diflerent pressures along its extension;

means for selectively air conduotively interconnecting said chamber with points of different pressure of said duct means;

and means for linking said chamber defining means to said duct means so that said duct means follow the expansion movements of said chamber as resulting from deflation and inflation thereof.

6. A suspension system for GEMs, an air duct having a cross section contracting from top to bottom and terminating in a downwardly directed nozzle, to direct air toward ground and to provide a pressurized air cushion underneath said GEM;

a tube of variable volume positioned relative to said air duct;

an air passage system selectively connecting said tube to said air duct at different points of pressure in said air duct to establish in said tube different pressures thereby to vary the volume of said tube, said tube of variable volume including a movable pressure pad exposed to the pressure at a portion of said air cushion, and having its position determined by the pressure balance between the pressure underneath said pad, and the pressure in said tube;

means for transmitting any change in position of said pad as adjustment to said air passage system for changing the selective air conductive connection from said tube to said air duct;

and means for transmitting changes in volume of said tube as adjusting motion upon said duct and said nozzle, to vary the distance of said nozzle from the bottom of said GEM.

7. A suspension system for GEMs, a stationary tube portion in said GEM and a movable tube portion telescopically positioned to said stationary tube portion to provide therewith a chamber of variable volume, said movable tube portion having a downwardly directed wall portion moving with said movable tube portion relative to said GEM;

means for pressurizing said chamber;

vertically adjustable and downwardly directed nozzle means for directing pressurized air towards the ground to provide an air cushion underneath said wall portion, so that the position of said movable wall portion is determined by the pressure in said chamber; and means for imparting movements of said movable tube portion as position adjusting movements upon said nozzle means to vertically adjust the distance of said nozzle means from the bottom of said GEM. b 8. In a suspension system for GEMs, a stationary mem- 55 er;

a movable control member establishing with said stationary member a deflatable and inflatable pressure chamber of variable volume, the position of said movable member depending upon the pressure balance between the pressure in said chamber and the pressure underneath said GEM; nozzle means for establishing an air cushion underneath said GEM and said movable control member outside of said chamber;

adjustable vane means in said nozzle means for controlling the direction of air flow through said nozzle means;

and means for coupling said nozzle means directly to said movable control member during inflation and deflation of said chamber, to change the distance of said nozzle means from said GEM.

9. In a suspension system for GEMs, means defining a pressure chamber, a first, movable member included in said means and being positioned for varying the volume of 75 said chamber;

means for introducing relatively high pressurized air into said chamber upon adjustment of said first member in a first direction and within a limited range of movement;

means for introducing relatively low pressurized air into said chamber upon adjustment of said first member in a second direction within a limited range of movement in said second direction;

a second member responsive to the pressure underneath said GEM and being coupled to said first member to move said first member in response to any change in the pressure balance of the pressure underneath said second member and the pressure in said chamber;

a movable nozzle directing pressurized air underneath said GEM;

and means coupling said nozzle to said member to follow movements of said member in said first and sec- 0nd directions to an extent exceeding said limited ranges.

References Cited by the Examiner UNITED STATES PATENTS 3,073,549 1/63 Grii'fith 180-7 3,107,071 10/63 Wessels l807 FOREIGN PATENTS 136,636 3/61 Russia. 1,238,499 7/60 France. 1,258,780 3/61 France. 1,263,704 5/61 France.

15 A. HARRY LEVY, Primary Examiner.

PHILIP ARNOLD, Examiner. 

1. IN A SUSPENSION SYSTEM FOR GEM''S, MEANS DEFINING A PRESSURE CHAMBER OF VARIABLE VOLUME, AND INCLUDING A MEMBER DISPOSED UNDERNEATH SAID GEM, SAID MEMBER BEING CAPABLE OF MOVING RELATIVE TO SAID GEM TOWARDS AND AWAY THEREFROM THEREBY CHANGING THE VOLUME OF SAID CHAMBER; MEANS INCLUDING MOVABLE NOZZLE MEANS FOR DIRECTING PRESSURIZED AIR FROM SAID GEM TOWARD THE SURFACE UNDERNEATH THEREOF AND ESTABLISHING A PRESSURE CUSHION UNDERNEATH SAID GEM AND SAID MEMBER, THE POSITION OF SAID MEMBER AT ANY INSTANT BEING DETERMINED BY THE PRESSURE BALANCE BETWEEN THE PRESSURE IN SAID CHAMBER AND THE PRESSURE OF SAID CUSHION UNDERNEATH SAID MEMBER; AND MEANS FOR COUPLING SAID MEMBER DIRECTLY TO SAID MOVABLE NOZZLE MEANS SO THAT SAID NOZZLE MEANS FOLLOW THE MOVEMENT OF SAID MEMBER TO CHANGE THE DISTANCE OF SAID NOZZLE MEANS FROM SAID GEM IN RESPONSE TO VARIATIONS OF SAID PRESSURE BALANCE. 